How would you like to install.
select "Template" option.
Which blog posts should have IntenseDebate comments enabled?
Only on new posts
Your old comments will be displayed using your blog's native comment system
On all blog posts
IntenseDebate comments will be available on all posts, but your existing comments will be hidden.
Select "On all blog posts" option.

3.Scroll down to the bottom of the instructions.
4. Log in to your blogger dashboard--> Design--> Edit html.
back up your template

Now upload the template you have backup to IntenseDebate
After Uploading